Methods for enhancing plant health, protecting plants from biotic and abiotic stress related injuries and enhancing the recovery of plants injured as a result of such stresses

ABSTRACT

The present invention relates to a method of enhancing the health of plant or seed in order to protect a plant or a seed from a stress-related injury by treating a plant with a composition containing at least one lysophospholipid. The present invention further relates to a method of enhancing or accelerating the recovery of an injured plant by treating such injured plant with a composition containing at least one lysophospholipid. Finally, the present invention relates to a method of enhancing the germination of seeds and seedling vigour by treating seeds with a composition containing at least one lysophospholipid.

This invention was made with no United States government support.

FIELD OF THE INVENTION

The present invention relates to a method of enhancing plant or seedhealth in order to protect plants or seeds from stress-related injuries.Additionally, the present invention relates to a method of enhancing oraccelerating the recovery of plants suffering from stress-relatedinjuries. Finally, the present invention relates to a method ofenhancing the germination of seeds and seedling vigour.

BACKGROUND OF THE INVENTION

The yield and quality of desired plant products is determined by thehealth of the plant. A healthy plant is one which is able to withstandbiotic (pathogens, insects, etc.) stresses as well as abiotic (cold,heat, drought, etc.) stresses. Conversely, a weak plant is one whichsuccumbs to pathogen and/or environmental stresses. During imbibation,dry seed experiences stresses due to sudden rehydration. These stressescan impact both the extent and speed of seed germination. A healthy seedis one which is able to germinate faster and thus get a head start. Sucha head start improves the seed's chances of increasing its yield,especially in areas with shorter growing seasons. The commercial valueof seed is determined in part on percentage (%) germination, rate ofgermination and the robustness of the seedling produced. There is agreat interest in improving these properties of commercial seeds.

Mature seeds of most crop plants contain very little moisture. Theseseeds can be stored for a long time in dormant stage. The living portionof the seed, the embryo, remains inactive in dehydrated state as long asthe seed is remains dry. When these seeds are sown in the soil a rapidrehydration occurs. During this process, the embryo cells rehydrate andexpand. Cell membranes are assembled into an organized structure thatpreserves the integrity of the cells. However, since rehydration isgenerally quick, the cell membrane is not fully assembled in the initialphase of rehydration. This results in some leakage of cellular contents.During rehydration, since membranes are ‘leaky’. Important molecules,including proteins, carbohydrates and inorganic molecules, are known toleak in the initial phase of rehydration. This leakage of importantcellular constituents is known to cause injury or stress to the embryo.Leakage of cellular constituents has been associated with the failure ofseeds of many crops plants to germinate and/or produce healthyseedlings. Many seeds fail to germinate if the leakage of cellularsolute is significant. “Seed priming” is intended to impart “health” tothe embryo cells so that leakage (thereby injury) to the embryo can beminimized.

The injury of crops as a result of abiotic and biotic stresses has beena major problem in the agricultural production areas of the U.S.Specifically, over 60% of the crop loss for last 50 years has been dueto abiotic stresses (see USDA Agricultural Statistics, 1998). Abioticstresses include chilling, freezing, drought, heat, and otherenvironmental factors. In 1996, the loss of crop yield due to abioticstresses was recorded to be more than a billion dollars in the U.S. (seeUSDA Agricultural Statistics, 1998). Thus, there is a tremendousinterest in the plant industry to find a technology that can be used toprevent or mitigate stress injury and to accelerate recovery following astress injury.

Lysophospholipids are derived from membrane phospholipids by the removalof a fatty acid by the action of an enzyme phospholipase A2.Lysophospholipids are naturally present in plant and animal tissues, andcan be found in high concentrations in egg yolk, brain tissue, andsoybeans. Lysophospholipids are available commercially from Avanti PolarLipids, Inc. (Alabaster, Alabama) and from Sigma Chemical Co. (St Louis,Mo.). Lysophospholipids, such as lysophosphatidylethanolamine(hereinafter referred to as “LPE”) and lysophosphatidylinositol(hereinafter “LPI”), have been exploited for accelerating fruitripening, enhancing fruit stability during storage, and increasing theshelf life by retarding senescence of plant tissues such as fruits,vegetables, and cut-flowers. Farag, K. M. et al., Physiol. Plant,87:515-524 (1993), Farag, K. M. et al., HortTech., 3:62-65 (1993), Kaur,N., et al., HortScience, 32:888-890 (1997), Ryu, S. B., et al., Proc.Natl. Acad. Sci. USA, 94:12717-12721 (1997). Methods for using LPE toenhance fruit ripening and storage stability are disclosed in U.S. Pat.Nos. 5,126,155 and 5,100,341. Methods for using LPE with 18:1 fatty acidand LPI to retard senescence and to enhance fruit ripening is describedin WO 99/23889.

SUMMARY OF THE INVENTION

The present invention relates to a method of enhancing plant or seedhealth in order to prevent injuries to a plant or seed upon exposure toa stress. The method involves applying to a plant or seed beforeexposure to a stress, an effective amount of a composition containing atleast one lysophospholipid(s) and optionally, at least one activatingagent. The preferred lysophospholipids contained in the composition areLPE and LPI.

Additionally, the present invention further relates to a method ofenhancing the recovery of a plant injured as a result of stress. Themethod involves applying to a plant after exposure to stress, aneffective amount of a composition containing at least onelysophospholipid(s) and optionally, at least one activating agent. Thepreferred lysophospholipids contained in the composition are LPE andLPI.

Finally, the present invention relates to a method of enhancing thegermination of seeds. The method involves treating seeds with acomposition containing at least one lysophospholipid(s) and optionally,at least one activating agent. The preferred lysophospholipids containedin the composition are LPE and LPI.

BRIEF DESCRIPTION OF THE FIGURES

The file of this patent contains at least one drawing executed in color.Copies of this patent with color drawing(s) will be provided by thePatent and Trademark Office upon request and payment of the necessaryfee.

FIG. 1A and FIG. 1B show LPE protection of tomato plants from a chillinginjury when said plants are sprayed with LPE about 1 hour prior tochilling.

FIG. 1C shows LPE protection of cucumber plants from a chilling injurywhen said plants are sprayed with LPE about 1 hour prior to chilling.

FIG. 2 shows the recovery of vigorous shoot growth in LPE 18:1 sprayedtomato plants compared to water-sprayed plants 7 days after droughtstress.

FIG. 3 shows the vigorous shoot growth in plants treated with either LPE18:1 or LPI as compared to plants treated with water (control) 10 daysafter spraying with a pesticide.

FIG. 4 shows the protection of castor bean seedlings from wound-damagebe spray application of LPE as compared to plants sprayed with water(control).

FIG. 5 shows the protection from microbial injury in smooth bromegrassleaf by spray application of LPE and LPI prior to microbial infection.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the present invention relates to a method ofenhancing plant health in order to protect a plant or a seed fromstress-related injuries upon exposure to one or more stresses. In asecond embodiment, the present invention relates to a method ofenhancing or accelerating the recovery of an injured plant afterexposure to a stress. Each of these methods involves applying to a plantor a seed, either before and/or after exposure to a stress, acomposition containing at least one lysophospholipid(s) and optionally,at least one activating agent. In a third embodiment, the presentinvention relates to a method of enhancing germination of seed. Thismethod involves treating seed with a composition containing at least onelysophospholipid(s) and optionally, at least one activating agent.

As used herein, the term “stress injury” refers to an injury resultingfrom an abiotic and/or a biotic stress. As used herein, the term“abiotic stress” refers to those non-living substances or environmentalfactors which can cause one or more injuries to a plant. Examples ofabiotic stresses include those injuries which result from chilling,freezing, hail, flooding, drought, soil compaction, soil crusting andagricultural chemicals such as pesticides and herbicides. For seeds,rapid rehydration during the initial phase of seed germination isconsidered to be an abiotic stress. As used herein, the term “bioticstress” refers to those living substances which cause one or moreinjuries to a plant. Examples of biotic stresses include those injuriesresulting from infections by insects, nematodes, snails, mites, weeds,pathogens, such as fungus, bacteria or viruses, and physical damagecaused by people and animals (i.e. grazing, tredding, etc.).

As used herein, the term “plant” refers to a whole live plant as well asto any part, tissue or organ from a live plant. For example, the term“plant” includes fruit, flowers, tubers, roots, stems, hypocotyls,leaves, petioles, petals, seeds, etc. The plants of the presentinvention may be planted in the terra firma, such as a field, garden,orchard, etc., or may be in a pot or other confined growing apparatus(such as a window box, etc.).

As discussed above, the methods of the present invention employ acomposition containing at least one lysophospholipid and optionally, atleast one activating agent. Additionally, the composition of the presentinvention may contain combinations of a number of lysophospholipids andactivating agents.

As used herein, the term “lysophospholipids” refers to derivatives ofphospholipids having a single fatty acid removed. Specifically, thelysophospholipids contained in the composition have the formula:

wherein R¹ is selected from the group consisting of C₅-C₂₂ acyloxy andC₅-C₂₂ alkoxy group; R² is selected from the group consisting ofhydrogen, hydroxyl, C₁-C₅ acyloxy and C₁-C₅ alkoxy group; and R³ isselected from the group consisting of hydrogen, choline, ethanolamine,glycerol, inositol and serine, wherein R¹ and R² are interchangeable.

Examples of lysophospholipids having the above formula and which can beused in the composition include LPE, LPI, LPC, LPG, LPS, LPA andcombinations thereof (LPC=Lysophosphatidyl choline; LPG=Lysophospatidylgycerol; LPS=Lysophatidyl serine; and LPA=Lysophosphatidic acid).

Preferably, the composition contains an acceptable carrier for thelysophospholipids, such as water. However, other carriers, such asorganic solvents, can also be used. The amount of lysophospholipid(s)contained in the composition is an amount which is effective to preventinjury from a stress and/or enhance or accelerate the recovery of aplant or a seed after exposure to said stress. Preferably, the amount oflysophospholipid in the composition is in the range of from about 1.0 toabout 400 mg per 1 liter of the composition according to the planttreated.

In addition to containing the lysophospholipids, the composition mayoptionally contain one or more activating compounds. As used herein, theterm “activating compounds” refers to agents that enhance wettability,uptake and effectiveness of an active ingredient. In the composition,the active ingredient is the lysophospholipid(s). Examples of activatingcompounds that can be used in the method of the present inventioninclude ethanol, TERGITOL® (TERGITOL® is a nonylphenol polyoxyethyleneether. TERGITOL® is a registered Trademark of Union Carbide Chemicalsand Plastics Company, Inc., available from Sigma Chemical Company, St.Louis, Mo.) and SYLGARD® 309 (SYLGARD® 309 is 76% siloxylated polyetherand 24% of a surfactant mixture. SYLGARD® is a registered trademark andSYLGARD® 309 is available from Dow Corning Co., Midland, Mich.). Theactivating compounds can be present in the composition in the amount offrom about 0.05% to about 5% (v/v) of the composition.

The composition can be applied to the plant in any form. Preferably, thecomposition is applied as spray or simply dipping the plant in thesolution.

The composition described herein can be applied to a plant or a seed anytime prior to the time the plant or a seed is exposed to a stressinjury. Preferably, the plant is treated with the composition at leastone hour prior to exposure to a stress injury.

Additionally, the composition described herein can be applied to a plantwhich has been exposed to a stress injury in order to enhance oraccelerate the recovery of such injured plant. As used herein, the term“enhancing recovery” means that the plant is able to reverse the effectsof the stress injury faster and more efficiently than a non-treatedplant. The composition can be applied to a plant any time after injuryhas occurred. Preferably, the composition is applied to the plantimmediately after the injury to the plant occurs.

The present invention also relates to a method of enhancing germinationof seed. The method involves treating seed with the compositiondescribed hereinbefore for a period of time of from about 15 minutes toabout 5 hours. Preferably, the seed is soaked in the compositiondescribed herein for 2 hours. After seeds are treated with thecomposition they may either be planted or dried and stored usingtechniques known in the art. Prior to planting, the treated and driedseeds are preferably rehydrated in water or the composition may alsocontain an activating agent allowed to imbibe water in order tofacilitate germination. The seeds may then be planted using techniquesknown in the art.

By way of example, but not limitation, examples of the present inventionshall now be given.

EXAMPLE 1 Protection of Chilling Injury and Enhancement of RecoveryExample 1a

Tomato Plants cv. H9144 (cultivar of Heinz Co.) were grown in 20-literpots containing peat-lite mix (Readi-earth, Scotts, Marysville, Ohio) ina greenhouse which was supplied with additional tungsten light for a 16hour photoperiod. One month-old tomato seedlings were sprayed to thepoint that solution started to run off the leaves with 200 mg/L ofLPEegg (LPE extracted from egg) solution 1 hour before or right afterchilling. Control leaf branch was sprayed with distilled water. The LPEsolution was prepared by suspending 200 mg of crude LPEegg (Avanti PolarLipids, Inc., Alabaster, Ala.) in one liter of distilled water and thensonicating for 1 minute before spraying. After 4 days of chillingtreatment at 4/2° C. day/night temperatures and a 16 hour photoperiodwith 200 μmol m⁻² s⁻¹ fluorescent light intensity, plants weretransferred to a growth chamber maintained at 24/18° C. day/nighttemperatures and a 16 hour photoperiod with 400 μmol m⁻² s⁻¹ offluorescent light intensity. As shown in the photograph in FIG. 1A,water-sprayed leaf branches (control) showed severe chilling damage(leaf yellowing and death) and no shoot growth indicating chillinginjury in the growing point of the shoot (meristem). Whereas,LPE-treated leaf branch showed mitigation of chilling damage to theleaves and exhibited enhanced shoot meristem growth compared to thecontrol. When measured 10 days after chilling, LPE-sprayed leaf tissues,either before or after chilling, had higher levels of water,chlorophyll, and phospholipid content than water-sprayed control (seeTable 1 below). All these measurements demonstrate protection ofchilling injury by LPE. FIG. 1A shows LPE protection of chilling injurywhen LPE was sprayed 1 hour before chilling.

TABLE 1 Leaf Water Leaf (fresh/dry Leaf Chlorophyll Phospholipids wtratio) (mg/g dry wt) (nmol/mg dry wt) Treatment Mean ± SE Mean ± SE Mean± SE Experiment 1. When plants were sprayed right after chilling. Water9.57 ± 1.0 16.5 ± 4.0 18.0 ± 3.0 LPE (200 mg/L) 10.81 ± 0.5  28.2 ± 4.025.7 ± 1.0 Experiment 2. When plants were sprayed 1 hour beforechilling. Water 9.13 ± 0.2 13.5 ± 0.1 23.6 ± 1.0 LPE (200 mg/L) 10.1 ±0.4 21.6 ± 0.1 25.9 ± 0.3

Example 1b

As described above in Example 1a, one month-old tomato seedlings weresprayed either with 100 mg/L of LPEegg, distilled water (sprayedcontrol) or none (non-sprayed control) 1 hour before chilling. Chillingand recovery conditions were the same as in Example 1a above. As shownin FIG. 1B, non-sprayed leaf showed more damage compared to thewater-sprayed (control) leaf. This result indicates that whilewater-spraying itself can mitigate some chilling damage, spraying LPEsolution is most effective in protecting the plant from chilling injury.

Example 1c

Cucumber (Cucumis sativus inbred line-WI2238) plants were grown in 4liter plastic pots containing a sterilized mixture ofpeat:sand:composited soil:field soil (1:1:1:1, v/v) at a greenhouse.Growing conditions and other details were same as in Example 1a. Threeweek-old cucumber seedlings were sprayed with LPEegg (100 mg/L) twice, 1hour before chilling and then right after chilling. After 2 days ofchilling treatment at the same conditions as in Example 1a , plants weretransferred to a growth chamber maintained at 23±2° C. temperature and16 hour photoperiod with 400 μmol m² s⁻¹ of fluorescent light intensity.Both control (water-sprayed) and LPE-sprayed plants showed severechilling damage in leaves but only the LPE-sprayed showed vigorous shootgrowth after 7 days indicating recovery of shoot meristem from chillinginjury (see FIG. 1C which is a photograph taken 7 days after chilling).

EXAMPLE 2 Protection of Drought Injury and Enhancement of Recovery

Tomato plants cv. H9478 (cultivar of Heinz Co.) were grown in 20 literpots and placed in a growth chamber maintained at 24/18° C. day/nighttemperatures and a 16 hour photoperiod with 400 μmol m⁻²s⁻¹ ofcool-white fluorescent lights. Two month-old plants were sprayed witheither distilled water, LPEegg (100 mg/L) or LPE 18:1 (100 mg/L) beforeexposure to drought stress. Drought stress was given by withholdingwater for 2 days. The plants were sprayed once again with distilledwater, LPEegg (100 mg/L) or LPE 18:1 (100 mg/L) right after water wasgiven (alleviation of water stress). During drought stress, all water,LPEegg-and LPE 18:1-sprayed plants were severely wilted but regainedturgor soon after water was given again. Control (water-sprayed) plantsshowed retarded shoot growth, while LPEegg-and LPE 18:1 sprayed leafshowed vigorous shoot growth after 2 or 3 days. FIG. 2 shows vigorousshoot growth in a LPE 18:1-sprayed plant but poor shoot growth in awater-sprayed plant 7 days after drought stress was alleviated.

EXAMPLE 3 Protection of Pesticide-injury and Enhancement of Recovery

Marathon with active gradient of imidacloprid (available from OlympicChemical Co., PO Box K, Mainland, Pa.) is a pesticide used forcontrolling whitefly in plants. This is a systemic pesticide and isintroduced to the plant via soil application. As the pesticideaccumulates in the foliage the insects feeding on the plants are killed.Sometimes as this chemical accumulates in the plant it can result inphytotoxicity to the plant. To test this, tomato plants cv. H9144(cultivar of Heinz Co.) were grown for two (2) months in 20 liter potsin a greenhouse. Seven days after the pesticide Marathon was introducedinto the soil in powder form onto the pots, the plants showed leafdamage caused by this pesticide. Many leaves lost chlorophyll and plantshad poor shoot growth. Three weeks after the treatment of pesticide,LPEegg, LPE18:1 or LPI (200 mg/L each) solution containing 1% ethanolwere sprayed to the point that solution started to run off the leaves.Control plants were sprayed with distilled water containing 1% ethanol.The LPE solution was prepared by wetting 200 mg of LPE in 1 ml ethanoland then adding distilled water to make 1 liter of total volume. The LPEsolution was then sonicated 1 minute before spraying. While controlplants continued to have poor shoot growth, plants sprayed withlysophospholipids such as LPEegg, LPE18:1, and LPI resumed shoot growthwithin 4-5 days after spraying. FIG. 3 is a photograph showing vigorousshoot growth in LPE18:1 or LPI-sprayed plants 10 days after spraying,compared to poor shoot growth in the plants sprayed with water(control).

EXAMPLE 4 Protection of Wound-damage and Enhancement of Recovery

Many insects cause wounding of plants. Studies aimed at simulatinginsect damage commonly use pliers to cause wounding of plants. Forexample, in a recent study, this technique was used for castor beanleaves (Ryu, S. B. et al., Biochimica et Biophysica Acta, 1393:193-202(1998). Coatless castor bean (Ricinus communis L. cv Hale) seeds weregerminated in the dark in moist vermiculite for 3 days. The seedlingswere individually transplanted into plastic pots containing a mixture ofvermiculite and perlite (1:1, v/v) that were subirrigated with Hoaglandnutrient solution (details described in Ryu, S. B. et al., Biochimica etBiophysica Acta, 1393:193-202 (1998)). Plants were grown undercool-white fluorescent lights at 23±2° C. with a 14 hour photoperiod.Fully expanded leaves from approximately 8-week-old plants weremechanically damaged with pliers, and then right away water or LPEegg(100 mg/L) was sprayed onto the wound areas, respectively. Control(water-sprayed) part of the leaf showed leaf curling-up and the leavesturned brown after 1 day, while LPE-sprayed part showed much less leafcurling and browning (FIG. 4). LPE-sprayed leaves remained turgid forseveral days. Wound-healing symptoms in LPE-sprayed leaf part wereobserved (specifically, leaf damaged areas were healed and gained greencolor).

EXAMPLE 5 Protection of Microbial Infection and Enhancement of Recovery

Smooth bromegrass (Bromus inermis Leyss.) plants were grown in 4 literplastic pots in a greenhouse. Growing conditions and other details weresame as described in Example 1a .

Water or a mixture of equal parts of LPEegg/LPE18:1/LPI (25 mg/L,respectively) was sprayed on to the plants 1 hour before the spraying ofa fungus (Cochliobolus sativus) suspension solution. This fungus isknown to cause spot blotch or foot (crown) and root rot of temperatecereals and turf grasses (Braverman, S. W., Bot. Rev., 52:1-115 (1986)).Fungus suspension solution was prepared by mixing fungus grown in agarmedia with distilled water. After a 2 day incubation in a humid chamber,the plants were transferred back to the greenhouse. Three to five daysafter fungus inoculation, water-sprayed control grass plants showedsymptoms of leaf lesions such as purplish brown spots scattered all overareas of the leaves and the leaf damage was apparent even after 2 weeks.In contrast, LPE and LPI mixture-sprayed plants showed less fungusinfection symptom and the leaf damage was dramatically healed in 2 weeks(see the photograph in FIG. 5 which was taken 12 days after fungusinoculation).

EXAMPLE 6 Enhanced Germination of Sweet Corn Seeds

Sweet corn seeds (SS Jubilee, certified seed obtained from the WisconsinCrop Improvement Association, Madison Wis.) were soaked for 2 hours inLPE solution. Seeds were removed from the LPE solution and 50 seeds wereplaced on 2 paper towels and wetted with distilled water (5 seeds in onerow) then seeds were covered with another wet paper towel. The threetowels with the seeds were rolled, placed in a metal container andincubated at 25° C. The container was covered with plastic and the coversecured with a rubber band. The germination percentage was tested after4 and 7 days. The procedure was as specified by the Association ofOfficial Seed Analysts. Four replications were conducted with 50 seedsin each replication. The results are shown below in Table 2. Theseresults show that soaking the seeds in LPE solution, especially at 5 and10 ppm concentrations, dramatically increased the numbers of seeds thatgerminated. Furthermore, LPE treated seeds produced larger (root andshoot) seedlings.

TABLE 2 Average Fresh Mass % Germination* Produced from 50 seedsTreatments After 4 days After 7 days Root**(g) Shoot(g) Water 53.5 ± 1.357.5 ± 1.3 1.0 ± 0.1 7.6 ± 0.3 LPE (5 ppm) 61.0 ± 1.7 70.0 ± 2.2 1.6 ±0.4 10.0 ± 0.5  LPE (10 ppm) 69.0 ± 2.6 71.5 ± 2.8 1.3 ± 0.1 8.7 ± 0.2LPE (20 ppm) 60.0 ± 3.6 65.0 ± 1.3 1.2 ± 0.0 10.4 ± 0.4  *Mean ± SE.(Average of four replications, each replication contained 50 seeds)**Primary + secondary roots.

EXAMPLE 7 Enhance Germination of ‘SS Jubilee’ Sweet Corn Seeds

SS Jubilee sweet corn seeds were soaked for 2 hours in LPE solution.Seeds were incubated using the same procedure described in Example 6.The germination percentage was tested after 4 and 7 days. Fourreplications were conducted with 50 seeds in each replication. Theresults are shown below in Table 3. Again, as in example 6, LPE (10 ppm)treated seeds showed better germination and gave more robust (largersize) plants. On a commercial level, this means that LPE treatment ofthe seeds will insure more plants in a given field and that LPE treatedseeds will produce plants having a head start.

TABLE 3 Average Fresh Mass** % Germination* Produced from 50 seedsTreatments After 4 days After 7 days Root**(g) Shoot(g) Water 58.0 ± 2.463.0 ± 1.8 0.8 ± 0.2 7.8 ± 0.5 LPE (1 ppm) 68.5 ± 4.0 76.5 ± 4.6 0.9 ±0.1 9.1 ± 0.8 LPE (10 ppm) 61.5 ± 5.7 68.0 ± 3.4 0.8 ± 0.0 7.6 ± 0.3 LPE(10 ppm) 73.8 ± 2.8 78.0 ± 2.3 1.1 ± 0.1 10.4 ± 0.4  **Mean of 40separate measurements ***Primary + secondary roots *Mean + SE (Averageof four replications, 50 seeds in each replication)

EXAMPLE 8 Enhanced Germination of H.2350 Field Corn Seeds

H.2350 (Certified seed obtained from the Wisconsin Crop ImprovementAssociation, Madison, Wis.) field corn seeds were soaked in LPEsolution. Seeds were incubated at 25° C. for 8 days using the proceduredescribed in Example 6. Four replications were conducted with 50 seedsin each replication. The results are shown below in Table 4. As with thesweet corn (SS Jublilee), LPE treatment of field corn seed improved seedgermination (although even the water treated seeds demonstrated goodgermination) as well as improved the size of seedling.

TABLE 4 Fresh Weight** Treatments % Germination* Root***(g) Shoot (g)Water 93.0 ± 1.0 12.7 ± 0.3 14.4 ± 0.2 LPE (5 ppm) 97.0 ± 0.6 14.2 ± 0.816.2 ± 0.6 LPE (10 ppm) 98.5 ± 1.0 13.6 ± 0.3 15.6 ± 0.7 *Mean ± SE(Average of four replications, 50 seeds in each replication) **Averagemass produced from 50 seeds ***Primary + secondary roots.

EXAMPLE 9 Enhanced Germination of ‘Hazel’ Oats

‘Hazel’ oats (Certified seed obtained from the Wisconsin CropImprovement Association, Madison, Wis.) were soaked in LPE or LPC. Seedswere soaked for either 30 minutes or 2 hours at room temperature (23±2°C.) and then incubated at 20° C. using the official seed germinationtest rules (Rules for testing seeds are published by the Association ofOfficial Seed Analysts) for testing seeds. Four replications wereconducted with 100 seeds in each replication. Results are shown below inTable 5. The results show that soaking seeds in LPE (10 ppm) or LPE andLPC (10 ppm each) increases the percentage of seeds germinated.Moreover, a greater proportion of the seeds treated with these lipids,germinated earlier. Thus, this seed treating increased both the rate andamount of seed germination.

TABLE 5 % Germination (Mean ± SE) After 4 days After 10 days Treatments30 min 2 hours 30 min. 2 hours Water 75.5 ± 1.9 75.5 ± 3.7 83.0 ± 1.687.3 ± 4.0 LPE (10 ppm) 87.7 ± 0.9 82.8 ± 1.1 91.3 ± 0.7 94.3 ± 1.3 LPE(10 ppm) 82.5 ± 1.7 82.0 ± 1.2 90.8 ± 1.1 93.5 ± 1.0 LPE + LPC (10 ppm85.5 ± 1.7 84.5 ± 1.7 92.0 ± 2.0 96.3 ± 0.5 each)

EXAMPLE 10 Enhanced Germination of ‘Hazel’ Oats

‘Hazel’ oat seeds were soaked in LPE or LPC for 30 minutes at roomtemperature (23±2° C.), then incubated at 20° C. to evaluate theinfluence on seedling vigour parameters (Root fresh weight and shootfresh weight). Values are mean±SE (4 replications). Results are shownbelow in Table 6. Seeds treated with LPE (10 ppm) had higher root andshoot fresh weight. Thus, LPE treatment increased seedling vigor.

TABLE 6 Root fresh wt Shoot Fresh wt per seedling per seedling Treatment(mg) (mg) Water 40.7 ± 3.0 121.8 ± 6.8 LPE (10 ppm) 48.4 ± 1.9 124.1 ±3.0 LPC (10 ppm) 40.4 ± 2.7 108.9 ± 4.5 LPE + LPC (10 ppm each) 43.1 ±2.5 115.0 ± 5.5

EXAMPLE 11 Enhanced Germination of ‘Hazel Oats’

‘Hazel’ oat seeds were soaked in LPE or LPC for 2 hours at roomtemperature (23±° C.), then incubated at 20° C. to evaluate theinfluence of LPE and LPC or seedling vigour (Root or shoot freshweight). Values are mean±SE (4 replications). Results are shown below inTable 7. Results show that either LPE or LPC alone or in combinationincreased both root and shoot fresh weight. Thus, two hour soaking inlipids resulted in enhanced seedling vigor.

TABLE 7 Root fresh wt Shoot Fresh wt per seedlings per seedlingsTreatments (mg) (mg) Water 41.1 ± 1.2 117.6 ± 6.0 LPE (10 ppm) 46.4 ±0.6 121.1 ± 2.5 LPC (10 ppm) 48.9 ± 0.7 130.4 ± 2.7 LPE + LPC (10 ppmeach) 48.8 ± 2.3 120.8 ± 2.1

All references referred to herein are incorporated by reference.

The present invention is illustrated by way of the foregoing descriptionand examples. The foregoing description is intended as a non-limitingillustration, since many variations will become apparent to thoseskilled in the art in view thereof. It is intended that all suchvariations within the scope and spirit of the appended claims beembraced thereby.

Changes can be made to the composition, operation and arrangement of themethod of the present invention described herein without departing fromthe concept and scope of the invention as defined in the followingclaims.

What is claimed is:
 1. A method of protecting a plant or a seed from astress injury, the method comprising the step of applying to a plant orseed in need of protection from a stress injury, an effective amount ofa composition comprising at least one lysophospholipid having theformula:

wherein R¹ is selected from the group consisting of C₅-C₂₂ acyloxy andC₅-C₂₂ alkoxy group; R² is selected from the group consisting ofhydrogen, hydroxyl, C₁-C₅ acyloxy and C₁-C₅ alkoxy group; and R³ isselected from the group consisting of hydrogen, choline, ethanolamine,glycerol, inositol and serine, wherein R¹ and R² are interchangeable. 2.The method of claim 1 wherein the composition further comprises at leastone activating agent.
 3. The method of claim 1 wherein thelysophospholipid is lysophosphatidylethanolamine,lysophosphatidylinositol or combinations thereof.
 4. The method of claim1 wherein the composition is an aqueous solution.
 5. The method of claim1 wherein the composition is applied onto the plant or seed beforeexposure to the stress injury.
 6. The method of claim 1 wherein thecomposition contains from about 5.0 to about 500 mg per liter oflysophospholipid.
 7. The method of claim 2 wherein the activating agentis ethanol, a nonylphenol polyoxyethylene ether or a siloxylatedpolyether.
 8. The method of claim 1 wherein the stress injury is theresult of an abiotic or a biotic stress.
 9. The method of claim 8wherein the abiotic stress is the result of chilling, freezing, wind,drought, heat, chemicals or imbibation.
 10. The method of claim 9wherein the chemical is a pesticide or herbicide.
 11. The method ofclaim 8 wherein the abiotic stress is imbibation during germination of aseed.
 12. The method of claim 8 wherein the biotic stress is the resultof infection by an insect, nematode or pathogen.
 13. The method of claim12 wherein the pathogen is a fungus, bacteria or virus.
 14. A method ofenhancing the recovery of an injured plant from a stress related injury,the method comprising the step of applying to the injured plant aneffective amount of a composition comprising at least onelysophospholipid having the formula:

where R¹ is selected from the group consisting of C₅-C₂₂ acyloxy andC₅-C₂₂ alkoxy group; R² is selected from the group consisting ofhydrogen, hydroxyl, C₁-C₅ acyloxy and C₁-C₅ alkoxy group; and R³ isselected from the group consisting of hydrogen, choline, ethanolamine,glycerol, inositol and serine, wherein R₁ and R₂ are interchangeable.15. The method of claim 14 wherein the composition further comprises atleast one activating agent.
 16. The method of claim 14 wherein thelysophospholipid is lysophosphatidylethanolamine,lysophosphatidylinositol, lysophosphatidylcholine or combinationsthereof.
 17. The method of claim 14 wherein the composition is anaqueous solution.
 18. The method of claim 14 wherein the composition issprayed onto the plant after exposure to a stress injury.
 19. The methodof claim 18 wherein the stress injury is the result of an abiotic or abiotic stress.
 20. The method of claim 19 wherein the abiotic stress isthe result of chilling, freezing, wind, drought, heat, chemicals orimbibation.
 21. The method of claim 20 wherein the chemical is apesticide or a herbicide.
 22. The method of claim 19 wherein the bioticstress is the result of infection by an insect, nematode or pathogen.23. The method of claim 22 wherein the pathogen is a fungus, bacteria orvirus.
 24. The method of claim 14 wherein the composition contains fromabout 5.0 to about 500 mg per liter of lysophospholipid.
 25. The methodof claim 15 wherein the activating agent is ethanol, a nonylphenolpolyoxyethylene ether or a siloxylated polyether.